diff --git a/src/rpn.rs b/src/rpn.rs
index 42b30a1..d1cd3c3 100644
--- a/src/rpn.rs
+++ b/src/rpn.rs
@@ -60,7 +60,7 @@ use sysexits::{ EX_DATAERR, EX_IOERR };
 #[cfg(target_os="openbsd")] extern crate strerror;
 #[cfg(target_os="openbsd")] extern crate openbsd;
 #[cfg(target_os="openbsd")] use strerror::StrError;
-#[cfg(target_os="openbsd")] use openbsd::{ Promises, pledge };
+#[cfg(target_os="openbsd")] use openbsd::{ Promises, pledge, unveil };
 
 #[derive(Clone, PartialEq, PartialOrd, Debug)]
 /* enum CalcType is a type containing operations used in the calculator */
@@ -225,10 +225,14 @@ fn main() -> ExitCode {
 	let argv = args().collect::<Vec<String>>();
 
 	#[cfg(target_os="openbsd")] {
-		let promises = Promises::new("stdio");
+		let promises = Promises::new("stdio unveil");
 		if let Err(e) = pledge(Some(promises), None) {
 			return err(&argv[0], &e, Some(EX_OSERR));
 		}
+
+		if let Err(e) = unveil(None, None) {
+			return err(&argv[0], &e, Some(EX_OSERR));
+		}
 	}
 
 	let mut stack = VecDeque::new();